Typically, non-metallic sheathed cable is attached to electrical junction boxes by either of two general methods. The classical method of connecting said non-metallic sheathed cable to an electrical junction box is by inserting a circular, threaded metal connector through a hole or knock-out in the junction box, mating the exposed end of the connector inside the box with a threaded flange, tightening the threaded flange against the connector and thus tightly to the wall of the junction box, inserting said non-metallic sheathed cable, orienting said cable in the proper orientation if it is an oval cross-directional shape, and then tightening two screws that draw together a bracket that is an integral part of said connector causing the bracket to draw together around said cable and lock it in place.
The second general method of attaching non-metallic sheathed cable, either circular or oval in cross-directional shape, employs quick connect type fittings that are pushed into the hole in the junction box either prior to the insertion of said cable or are inserted after being affixed onto the cable with the connector and cable then inserted together.
U.S. Design Pat. No. 251,781 shows a quick connect electrical connector that has a cutout area in its circumference as does the invention of this disclosure. This connector is difficult to use because it is hard to squeeze to a sufficiently small circumference to allow easy insertion in the hole or knock-out of an electrical junction box. The hinge and notched area of the top flange of this invention, which is an improvement to D-251,781, enable far easier insertion in a junction box with gentle pressure applied with one hand.
The connector of U.S. Pat. No. 4,299,363 consists of four equally sized tabs for gripping the wall of a junction box. Enough force must be exerted to overcome the resistance provided by the four tabs. There is no hinge in the outer perimeter of the connector, no necked down area to assist in the flexing of the connector and it is mentioned in '363 that insertion in the hole of a junction box "may be facilitated when necessary by a light tapping action" on the side of the connector "with a hammer where the sizing of the knock-out opening is somewhat smaller than will accomodate finger pressure application of the connector to the box knock-out opening".
U.S. Pat. Nos. 4,919,370 and 5,118,057 refer to connectors that are substantially different than the connector of this disclosure, being designed to be installed partially into a knock-out of a junction box prior to inserting the cable, and then installed completely once the cable has been inserted. There are many more steps involved than the simple finger pressure assisted installation of this invention. Both 4,919,370 and 5,118,057 mention that the external portion of the fitting may be adapted to provide a "rear-end striking surface" in one variation, another variation with "rearward facing screwdriver slots" to enable driving the fitting securely into the box with a screwdriver, and another variation in which the fitting may be affixed to the panel and locked by compression of gripping arms by an "ordinary pair of channelled adjustable pliers".
This disclosure thus improves all of the aforementioned prior art by providing a simple, one-piece moldable electrical connector that is flexible enough in its design to allow easy one hand insertion in the knock-out of a junction box while also providing one-way restraint of the cable at the junction box wall to prevent forceful removal therefrom.